FIG. 1 is a flow chart depicting a conventional method 10 for fabricating a conventional perpendicular magnetic recording (PMR) transducer. For simplicity, some steps are omitted. A conventional pole is provided, via step 12. The conventional pole is magnetic and has a top wider than its bottom. Step 12 typically includes depositing on or more high moment magnetic layers in the desired shape. For example, materials containing Co, Fe, and/or Ni with a high moment may be deposited in a trench having the desired trapezoidal profile or blanket deposited and subjected to a photolithographic process to provide the desired trapezoidal profile. In addition, the conventional pole is desired to have at least a trailing edge, or top, bevel. Thus, the conventional pole is desired to be shorter in the region of the air-bearing surface (ABS) location. The ABS location is the location at which the ABS will reside in the completed structure. In addition to the trailing edge bevel, the conventional pole may include a leading edge bevel.
To form the bevel, a mask is provided, via step 14. Step 14 may include providing bottom antireflective coating (BARC) and other layers as well as depositing and patterning a hard mask or other mask for bevel formation. A high energy ion mill is performed, via step 16. The ion mill is typically performed at an angle from normal to the surface to provide a sloped trailing edge bevel. The energy of the ion mill is typically seven hundred eV or greater. A high energy ion mill is desired in order to remove the pole material at a sufficiently high rate for the desired throughput in manufacturing processes. For example, the high energy ion mill may remove on the order of 1600-2000 Angstroms in a few minutes.
A conventional gap layer is provided, via step 18. Step 18 may include a brief sputter etch followed by deposition of the conventional gap layer. The conventional gap layer is nonmagnetic and may be insulating. The conventional gap layer is typically alumina deposited using atomic layer deposition (ALD). As a result, the conventional gap is conformal, covering the top and side of the conventional PMR pole.
Fabrication of the transducer is then completed, via step 20. For example, a wrap-around shield, coils, other shield(s) and other structures may be fabricated. In addition, the transducer is lapped to expose the ABS.
FIG. 2 depicts a portion of a conventional PMR transducer 50 formed using the conventional method 10. The conventional transducer 50 includes an underlayer 52, a conventional pole 54 including trailing bevel 56, and a conventional gap 58. Other structures (not shown) are also fabricated using the conventional method 10.
Although the conventional method 10 may provide the conventional PMR transducer 50, there may be drawbacks. In particular, the top layer of the pole may be damaged. As can be seen in FIG. 2, the pole 56 includes a damaged region 60. This region is generally amorphous instead of crystalline. The amorphous damaged region 60 has a lower saturation magnetic flux density (Bs) and lowers the overall Bs of the conventional pole 54. A reduction in the Bs of the pole is undesirable. Further, the damaged region 60 may result in the effective thickness of the gap 58 varying. Such a variation in the nonmagnetic gap 58 thickness is undesirable. Accordingly, what is needed is an improved method for fabricating a transducer.